I. Field of the Invention
The present invention relates to apparatus associated with a high speed inserting machine for collating different kinds of documents prior to an insertion operation.
II. Description of the Prior Art
Large volume, high speed collating and inserting machinery of the type having a series of document feeding stations located above a feed path have long been known. In such arrangements, typically, a conveyor is provided for collecting the documents from a plurality of feeding stations while collating the same and providing an envelope inserting station located downstream from the feeding stations for collectively inserting the collated documents into an envelope. Ever larger volumes of documents have created a need for ever increasing speeds of such machinery. Many of the presently commerically available collating and insertion machines operate on an intermittent or interupted basis. That is, often times, in the collection of documents at the respective feeding stations, the conveying mechanism is required to come to a full stop. Similarly, it often occurs that the conveying mechanism must come to a full stop for a subsequent insertion of the envelopes with the documents into their associated envelopes.
Such requirements for a halt in the operation at each station have been occasioned by designs that require the positive handling of the documents through clamps or opposed, closeable fingers. Of course, it will be appreciated that such expedients not only require intermittent drive operation, but also tend to skew and even occasionally tear documents. Additionally, the drive mechanisms of such intermittent operating machinery exhibit far greater wear than continuously operating machinery. The commonly assigned U.S. Pat. No. 4,169,341 to Roetter et al discloses on improvement to such apparatus and, specifically, collating and inserting apparatus that is capable of continuous operation resulting in substantially increased output.
Another drawback of the prior art resides in the fact that previously it was customary to collate a plurality of documents such that an address bearing document would be placed first in a stack of documents, face down. In this manner, when all of the documents had been fed into position and were subsequently turned over, the address bearing document would be face up and readable. The phrase "address bearing document" is taken to mean a document which recites the name and address of the person or organization to which all of the documents together are to be directed, as by the Postal Service.
Other typical conveyor systems known to the inventors are disclosed in U.S. Pat. Nos. 4,130,193 to Bourgeois and 4,499,834 to Ruetschle et al. In the Bourgeois machine, an interrupter unit is first operated to provide a gap in the flow of goods along a transferor conveyor. Thereupon, a control unit delays operation of a transfer unit until the gap created by the interrupter unit reaches the area where the transfer is to take place. At that point, when the area is free of goods, the transfer unit is operated and delivery begins from the transferor conveyor to the transferee conveyor and thence onto a subsequent operation. In the Reutschle et al machine, a plurality of sheets are fed from hoppers onto a support surface immediately ahead of a pusher finger after which the group of sheets is inspected for thickness. If the group of sheets does not pass inspection, a ramp is operated and opposed belts receive the group of sheets from the ramp and deposit them on a receiving tray positioned above the support surface for subsequent removal from the system.